Negative Power Supply Linear Regulator Design And Frequency Compensation And Transient Characteristics

Power supply management IC (integrated circuit) have broad market prospect related to their virtues with high integration density, high price performance ratio, the most simple periphery circuit, and the advantage that it can make high efficiency power supply, etc. The circuit proposed in this paper, or the negative linear regulator, belongs to the catalogue of power management The power devices working in the linear region makes it the main feature of this circuit; it also performs the features of high stability, good reliability and low cost. Nowadays, the market of this chip is monopolized by the corporations abroad, hence, it has magnificent sense to master this technique and do research around the key points of the design. In this paper, a negative linear regulator with NPN Darlington structure and its layout are designed using the mature bipolar process afforded by certain company. It has five optional output voltages: -5V, -12V, -15V, -18V, -24V with the minimum input voltage -40V, the maximum output current 100mA and the maximum junction temperature 150 ℃, internal frequency compensation makes it high stability, as well. This regulator has an excellent ability of regulation which can stabilize the output voltage to the maximum extent. Additionally, some sub circuits like thermal protection, current limitation and SOA (safe operation area)protection are included in the regulator, which makes the circuit along longevity under safer working condition. Many problems and how to eliminate the error caused by the process and the manufacture in a maximum extent are considered carefully during the design. By using the mature bipolar process from certain company and the exclusive SPICE model, the circuit achieves the design requirements through the simulation, the function of the circuit is also achieved by PCB testing circuit, and its practicability then is validated ulteriorly. Considering many factors adequately during the layout design, the layout which meets the design requirements is obtained through the standard design flow, and finally is passed the checkout in virtue of the software Cadence. An in-depth study is also made about the keystones and difficulties, which mainly focuses on improving problems of stability through frequency compensation and transient performance. Firstly, the basic theory is analyzed then the solution is...